Apparatus for applying metal straps



Sept. 5, 1944. re F. M MAHAN 2,357,480

APPARATUS FOR APPLYING METAL STRAPS Original Filed Oct. 15,1938 4Sheets-Sheet 1 A 9 v '10 D A 9 1 ,Afimm p U '1:

A A fi V A A D A A p A A g .2 3b 2 9 VV V VV V V VVV lNVENTO R Y RoY F.MCMAHAN TTORNEY Sept. 5, 1944. R. F. McMAHAN 2,357,480

APPARATUS FOR APPLYING METAL STRAPS Original Filed Oct. 15, 1938 4Sheets-Sheet 2 AEA a 2 an 162- 4- F 1 79 a I {6/ 762 6/2 {0 8 8d 2 poyFig. /0 2%,xm T T ATTORNEY Sept. 5, 1944.

MQMAHAN 2,357,480

APPARATUS FOR APPLYING METAL STRAPS Original Filed Oct. 15, 1938 4Sheets-Sheet I5 Fiy. /3

INVENTOR ROY F. MQMAHAN ATTORNEY Patented Sept. 5, 1944 UNITED STATESPATENT QFFICE 2,357,480 a i APPARATUS FOR APPLYING METAL STRAPS Roy F.McMahan, Avondale, near Louisville, Ky; Original application October 15,1938, SerialNo.

235,129. Divided and this applicationtApril: 1, 1942, Serial No. 437,301

7 Claims application, Serial Number 235,129, filed October 15,1938, andentitled Metal bound box.

In the aforesaid applicatiomthere is discloseda' wood box having a metalbinding-strap engaging one face of each of the respective box seefitFigure '5 is an end view of the binding-strap showing the cornerprotecting members 8/ and By before thesame are secured tothecorresponding side and end ofthe'box;

Figure 6 is a partialsectional-view of the binding-strap showing theconstruction and relation of the short teeth lllthat are pressedthrough'the relatively thin side'members of the box, and long tions. Thestrap is provided with a plurality of teeth 9 that .are pressed throughthe relatively teeth, struck therefrom and integral therewith, 10 thickend members of the box; I I

and each tooth has a flat shank extending through Figure 7 is a partialsectional view taken along its respective box section. The free-endportion lines l'! of F gu e 2 showing the shape o the of each tooth isfolded against the opposite face corner protecting member 81 after sameis seof the respective box section, and arched longitucure to itscorresponding box member;

dinally throughout the length thereof so that "the igure 8 is' a partialvertical sectional-view end edge of the tooth is curled into therespecshowing the preferred construction of the aptive box section;reenforcing means is formed in 'paratus employed to apply the metalbindingthe arched free-end portion of each tooth for sestrap to a box,and illustrating the teeth ID of curing the same in its folded positionagainst the the strap pressed through box members I and opposite face ofthe respective box section. There- Figure 9 is a so a partial verticalsectionalfore, it is the object of this invention to provide view ill tg the r pying apparatus a simple and effective apparatus for applyingsuch "su stantia y beginning h e s p of bending a metal binding-strap tothe respective sections th te th I d ner p t ng m s a of a box. intoapproximately arch-shape;

Another object of this invention is to provide F ure 10 is likewise apVertical Sectionala simple tool that is mounted upon a conventional -V ilu rat t ppp y apparatus power-driven punch-press, much in the sameubstantially completing the a f g p manner as a conventional formingdie, for applytion-required to curl the free-end edges of each ing thesaid strap to the respective sections of a et nd the f ee nd edge ofeach end-p wood box. tect-ing member into their respective box sections,Also, it is a further object of this invention to and substantiallybeginning the forming of the provide apparatus for applying ametal-binding r nforc a 90 e a e ee-end p strap to articles other thanthe wood box illust o of e ch tOOthtrated in my aforesaid application.Figure 11 is an enlarged partial elevational These and other objectswill be apparent to view of one of the tooth forming tools as viewedthose skilled in the art as the following descrip- I ng n s o ure 1 tionis read in connection with the accompany- F r l is an ed d View Of O e ofing drawings, in which: the tooth forming tools;

Figure 1 is a perspective view of a box having 40 Figure 13 is a partialsectional view showing a: metal binding-strap applied by the apparatusthe final shape of a tooth in secured relation with disclosed in thisinvention; its corresponding box member;

Figure 2 is an enlarged partial view of the Figure 14 isapartialsectional view taken along corner of the box illustrating teeth Sand l0lines I 4| 4 of Figure 13 showing the reenforcpressed through theirrespective box sections, and .45 d 90 formed in the arched free-end ofeach also showing the relation of the corner-protectt d ing members 8and 89 before the free-ends of Figure 15 is a partial vertical sectionalview ilsame are secured to the corresponding box secl st ti e tr p pp inppa us n no tions; condition, that is, the relation of the variousFigure 3 is a partial view showing the outer p rts te t e Press isloaded and before the press faceof the binding-strap that lies alongside 2 is op at d. Figure 15 also shows guide p ns P of th box; andlimit stops S holding the pressure plate l4 Figure 4 is a partial Viewshowing the outer in functional relationship with its associated face ofth binding-strap that li along end 4 parts, and the manner in which thedie H is assoof the box; V ciated with the head or ram of a:power press.

In the foregoing drawings, only vertical sectional-views of the formingtools are presented, as it is believed that these are the essentialviews required to gain a thorough understanding of the invention. Asillustrated in Fig. 15, it is to be understood that the tool holder IIis provided with a suitable mounting means so that the same is fixedlysecured to the reciprocating slide of a conventional power-drivenpunch-press, for vertically reciprocating the same relative to astationary table T that is fixedly secured to the stationary bolsterplate of a conventional power press. Therefore, it is to be understoodthat the metal binding-strap 8 rests upon the table T while thereciprocating forming tool consisting of pressure plate 14 and formingtools l2, etc., is moved downwardly into engagement with the respectivebox members and the teeth of the binding-strap.

The specific apparatus illustrated in the drawings, is primarilyemployedto secure a sheetmetal binding-strap to the respective sections of awood box. However, it will be apparent that the teachings of thisinvention may be utilized to secure metal binding-straps. to variouskinds of articles. Accordingly, it is important to observe the relationexisting between the inner faces of the arched ends of the forming toolsl2 and the outer faces of the teeth that are engaged by the respectiveforming tools.

For the specific relation between the various parts of the forming tool,reference is directed to the drawings.

Thus, in specifically describing the particular embodiment of mystrap-applying tool, I do not desire to be limited other than by thescope of the appended claims. Therefore, although the forming toolincludes depending arms IGI and arched contours [8 for securing theend-protecting members 8g to their respective box members, it is to beunderstood that these may be altered or omitted, without affecting theoperation of the pressure plate I 4 and forming tools I2. Thus, for amore complete understanding of the parts utilized in securing theend-protecting members 8g, reference is made to my earlier United StatesPatent Number 2,253,639Qissued August 26, 1941, and entitled Bendingdie; also for a more complete understanding of the method utilized insecuring these end-protecting members to their respective box sectionsreference is made to my earlier United States Patent Number 2,201,193,issued May 21, 1940, and entitled Hanger and method of attaching same.

In Figure l of the drawings, a box is shown having metal binding-straps8 secured to the respective sections of the box by means of thestrap-applying tools forming the primary object of this invention. Itwill be observed that the box is preferably constructed from five piecesof relatively thin timber, or similar material, to form the side membersI and 2, end members 4 and 5-, and bottom member 3. It will also beobserved that all of these box members are rigidly and permanentlysecured together by two metal binding straps 8 of specially constructedanglesection. V

Each face of these angled binding-straps has a series of teeth strucktherefrom, which teeth are adapted to be pressed into and throughjuxtapositioned faces of the box members, for rigidly and permanentlysecuring the same together without the use of nails, screws, battens, orother similar securing means. With particular reference to Figures 1 to7 inclusive, it will be observed that the teeth along each face of thebinding-strap have a triangula shape and project substantially at rightangles from the corresponding face thereof in substantially a fiatplane. In this respect, particular emphasis is made of the fact that theplane of each tooth is made to register with the grain of the timberforming the side, end and bottom members of the box. Thisconstructionand arrangement is clearly shown in Figure 1. The object of thisarrangement is not only to facilitate assemblage, but to provide theleast possible fracturing of the fibres of the timbers so as to affordthe greatest mechanical strength. This arrangement further minimizesrejects because of split timbers that would otherwise be encountered bynot having the plane of the teeth substantially parallel with the grainof the timbers. This arrangement further enables the teeth to be pressedinto and through the box members with the least possible disturbance totheir free projecting positions, thus assuring proper alignment of theteethwith their corresponding forming or clinching tools, hereinafterdescribed.

In arranging the box members prior to being assembled into the boxillustrated in Figure 1, two specially constructed angled binding-strapsof the required length and gage are provided, each strap having a seriesof teeth struck from each of its faces and substantially uniformlyspaced throughout its length. The particular relation of each tooth, oneto the other and to the grain of the timber, isclearly shown in Figure1.

In assembling the binding-straps with the box timbers, the two strapsare laid parallel on a stationary table T of a conventional power press,and the sides I, 2 and bottom 3 laid fiat-wise upon the upstandingfree-ends of the teeth projecting from the corresponding faces of thestraps, which relationship is shown in Fig. 15. The power press is thenoperated, and the reciprocating forming tool consisting of tool holderII and pressure plate l4 moves downwardly towards the box timbers. Thepressure plate l4 engages the timbers and presses the same downwardlysothat the upstanding teeth ID are pressed into and through the boxtimbers, observe Figures 1, 2, 8, 9, 10, 13 and 14. Each side membe Iand 2, and the bottom member 3 are spaced, and the upright face of eachstrap is formed with a V gap or mitre adjacent each junction of a sideand bottom member so that the box members can be subsequently folded toassume the position illustrated in Figure 1. Y

Referring now to Figures 8 to 12, and 15, it will be observed that thetool for pressing the teeth l0 intoand through the box timbers, and forsubsequently clinching same, comprises aseries of forming tools l2carried by a die block I l, and a pressure plate l4 normally biased awayfrom the die block H by suitable springs l2s disposed between the diebloclc ll and pressure plate M.

Thus, it will be apparent that the pressure plate I4 shown in Figures 8,9', 10 and 15, first contacts the box members I, 2 and 3, and pressesthe teeth l0 into and through same by force from the power presstransmitted to the saidplate through the springs l2s, which springs aresufficiently strong to effect penetration. As illustrated in Figure 8,each forming tool 12 engages its corresponding tooth l0 after the boxmember is pressed against therespective inner face of the binding-strap.l

I 2 has a concaved arcuate contour I21), and an arcuate beading rib I20located'centrally of the lower face of the forming tool l2. Note Figures11 and 12.

Thus, each arcuate beading-rib I20 engages the free-end of a tooth ID inits downward movei ment; and progressively rotates, or curls, thefree-end in the manner illustrated in Figures 8, 9 and 10, until thefinal position illustrated in Figures 13 and 14 is reached. Just priorto each tooth reaching itsfinal position, the resistance of thecompressed box member increases, and exerts: sufficient pressure topermit the beading-rib l2c of each tool to form a reenforcing bead inthe curled end of each corresponding tooth, as illus- "trated-i-nFigures13and 1'4. 7 I

It is important to note that my strap-applying apparatus provides aslight shearing of the fibres of the box timbers adjacent the innerfaces of the box members, so that each tooth is independently andsimultaneously curled to a position below the inner face of the boxmembers. This arrangement eliminates objectionable metallic projectionswithin the box that may otherwise injure the hands of those required tohandle the box.

Thus, with a single stroke of a conventional power press, the side andbottom members of the box are secured to the corresponding faces of thebinding-straps. In Figures 1, 2,5 and '7 to 10,.inclusive, it will beobserved that each end of the binding-strap 8 is provided with cornerprotecting and end securing members 8 and 8g, These members are eachcurled around the edge of the corresponding box timbers, and theirfree-ends driven into the corresponding member. particularly illustratesthe member 8 curled into the respective box section 4.

With reference to Figures 8 to 10 inclusive, it will be observed that Ihave provided arcuate faces l8, guides I62 and projections IQ forarching the members 89/, or 8], in accordance with the teachings of myaforesaid earlier Patents Numbers 2,253,639 and 2,201,193. It will alsobe observed that the face I9a between the arched contours I8 isdepressed, not only to provide the required projections I9 forpenetrating the surface of the box member to provide the final securingoperation for the members 80, but sufficient to provide a recess intowhich the pressure plate i4 moves during the operation of the tools I2upon the free-ends of the teeth I0.

As illustrated in Figure 12, the pressure plate I4 is provided with aseries of round apertures through which the respective forming tools I2operate. It will also be noted that each tool l2 has a fiat portion l2a,and it is to be understood that each tool [2 is secured to the die blockII by set screws l5, as illustrated in Figure 11,

It is also to be understood that the pressure plate I4 is provided withguide pins P and limit stops S so that the same is normally held in aposition relative to the forming tools l2 as shown in Fig. 15.Obviously, such expedients are well known to those skilled in the art,and it is not regarded necessary to elaborate upon their constructionand relation. It is to be understood that the construction andarrangement of the guide pins and limit stops for the pressure plate 14may take various forms without departing -cua te contours l 8,projections 19 and arms: I61,

Note Figure '7 which- -tice the same from the spirit of this invention,since the essential novelty of this invention resides in theconstruction of the forming tools l2, the relation of thesetools'relative tovthe teeth [0, and the use of the tools l2 incombination with the arcuate contours l8. Accordingly, it .is believedthat Figs. 8 to 12 and- 15; sufiiciently illustrate the invention sothat those skilled in the art may prac- Therefore, while I havedescribed and. illustrated the construction and relation of the toolsrequired to secure the binding-strap 8 to the sides and bottom of thebox, it is believed that it will-be apparent to those skilled in theart, the

required arrangement of the tools to secure the straps B to therespective ends of the box.

Thus, after the strap is secured to the side members! and 2, the sidemembers are bentupright at' the-initre joints asillustrated -in Figurel. The end members 4 and 5 are-then placed within the partiallyconstructed box, either separately or together, and subjected to theaction of suitable tools, made in accordance with the teachings of thosedescribed for the side and bottom members, for curling the teeth 9 intothe respective ends of the box and forming the reinforcing means in thearched ends thereof, as shown in Figures 13 and 14. In this respect, itis to be understoodthat the tools for the ends of the box are alsoprovided-with the required arfor curling the end protecting-members 8]as shown in Figure 7.

While Ihave shown and described 'what I con.- sider to be the mostpractical embodiment of my invention, it is to be understood thatvarious changes in construction may be made under the scope of theappended claims.

Having thus described my invention, I claim:

1. In apparatus for applying a metal bindingstrap having a plurality offastening projections formed integrally therewith to a Wooden member; aplurality of forming tools, one for each fastening projection, each toolhaving on its forming end a semi-circular concave-face; a pressure plateoperatively associated with the said forming tools; means fo moving thepressure plate against the said member to press simultaneously the saidfastening projections into and through the same; means forlongitudinally moving each forming tool against its respective fasteningprojection, to curl it into substantially arch shape and to force thefree end thereof into the opposite face of the said member; and meansoperatively associated with each forming tool for longitudinally dentingthe curled portion of each corresponding projection so as to re-enforcethe said fastening projection in its curled condition.

2. In apparatus for applying a metal bindingstrap having a plurality offastening projections formed integrally therewith to a wooden member; aplurality of forming tools, one for each fastening projection, each toolhaving on its forming end a semi-circular concave face having the planeof the extremity of its concave face substantially parallel with theplane of the extremity of the corresponding fastening projection, eachtool also having a convex rib extending circumferentially of its concaveface; means for longitudinally moving each tool against its respectivefastening projection, to curl it into substantially arch shape and toform a concave reenforcing bead longitudinally therein.

3. In apparatus for applying a metal bindingstrap having a fasteningprojection formed integrally therewith to a wooden member; means forlongitudinally moving a forming tool having on its forming end asemi-circular concave face, a convex rib extending circumferentially ofsaid face and an end edge of the concave face positioned just outsidethe projecting end of the said projection; and means for guiding theforming tool against the said projection to curl it into anapproximately arch-shaped clinched-end, force the free-end thereof intothe wooden member, and to form a concave re-enforcing beadlongitudinally of said clinched end.

4. In apparatus for applying a metal binding strap having a fasteningprojection formed integrally therewith to a wooden member, means forlongitudinally moving a forming tool having on its acting end asemi-circular concave face and a. convex rib extending circumferentiallyof said face, and means for guiding said forming tool against saidprojection to curl it into substantially arch-shape and to form aconcave reenforcing bead longitudinally therein.

5. In apparatus for applying a meta1 binding strap having a plurality offastening projections formed integrally therewith to a wooden member; aplurality of forming tools, one for each fastening projection, each toolhaving on its forming end a semi-circular concave-face, a convex ribextending circumferentially of the concave face and an end edge of theconcave face positioned above and just outside of the projecting end ofthe corresponding fastening projection; a pressure plate operativelyassociated with the said forming tools; means for moving the pressure,

plate against the member to press simultaneously the said fasteningprojections into and through the same; means for longitudinally movingeach forming tool; and means for guiding each forming tool against itscorresponding fastening projection to curl it into substantiallyarch-shape, force the free-end thereof into the opposite face of thewooden member, and to from a concave re-enforcing bead longitudinally ofthe arched end.

6. In apparatus for applying a metal binding strap having a fasteningprojection formed integrally therewith to a wooden member; a formingtool having on its forming end a semi-circular concave-face and a convexrib extending circumferentially of the said face; a pressure plateoperatively associated with the said forming tool; means for moving thepressure plate against the member to press simultaneously the saidfastening projection into and through the same; means for longitudinallymoving the forming tool; and means for guiding the forming tool againstthe said projection to curl it into substantially archshape and to forma concave re-enforcing bead longitudinally therein.

'7. In apparatus for applying a metal binding strap having a fasteningprojection formed integrally therewith to a wooden member; a formingtool having on its forming end an arched concave face for curling theprojection longitudinally into substantially arch-shape, and means forbending the arched projection laterally to reenforce the same in itsarched condition; means for longitudinally moving the forming tool andmeans for guiding the forming tool against the free end of the saidprojection to curl the projection into substantially arch-shape and tobend the arched projection laterally to re-enforce the same in itsarched condition.

ROY F. MCMAHAN.

